Wednesday, June 10, 2009

Output Post Processor

Post-processing actions are actions taken on concurrentrequest output. An example of a post-processing action is that used in publishingconcurrent requests with XML Publisher.

For example, say a request is submitted withan XML Publisher template specified as a layout for the concurrent request output.After the concurrent manager finishes running the concurrent program, it will contactthe OPP to apply the XML Publisher template and create the final output.

A concurrent manager contacts an available OPP process when a running concurrentrequest needs an OPP processing action. A concurrent manager uses a local OPPprocess (that, is, on the same node) by default, but will choose a remote OPP if no localOPP process is available.

There should always be at least one OPP process active in the system. If no OPP serviceis available, completed requests that require OPP processing will complete with a statusof Warning.

An OPP service is multi-threaded and will start a new thread for each concurrentrequest it processes. You can control the number of simultaneous threads for an OPPservice instance by adjusting the Threads per Process parameter for the instance.

If all the OPP services have reached their respective maximum number of threads, therequests waiting to be processed remain in a queue to be processed as soon as threadsbecome available.

If request throughput has become slow, you may want to increase thenumber of threads per process for the OPP. It is recommended that you keep thenumber of threads per process between 1 and 20.